It is generally accepted that an outboard motor should be mounted on the transom of a boat such that the cavitation plate of the motor runs across the surface of the water while the boat is being operated. At such a height, the cavitation plate will be appropriately positioned to carry out its function of preventing air from reaching the propeller area, thereby preventing cavitation or slippage of the propeller in the water that can reduce the efficiency of operation of the motor, while at the same time the water will produce only a minimum drag on the motor to be overcome by the motor during the operation of the boat.
However, when a boat is to be used for a variety of purposes, it is often found impractical to have the motor mounted in that manner. For example, an appropriate height setting for the motor where a boat is to be used as a work boat, operating at a relatively low speed but requiring maximum thrust, is generally such that the cavitation plate will be positioned one to three inches higher than the bottom of the boat. This same setting, however, would not be appropriate where the boat should, at some time be used for racing purposes. At the higher speeds involved in racing, the stern of the boat is lower in the water requiring a setting of the cavitation plate generally of the order of three to five inches above the bottom of the boat to prevent excessive drag and to permit maximum speed to be obtained with propellers designed especially for racing purposes.
Some attempts have in the past been made to provide a outboard motor mounting apparatus which will allow for the motor to be quickly raised or lowered as might be desired for a particular application. Examples of such devices are disclosed in U.S. Pat. Nos. 4,232,627 and 4,482,330, the disclosures of which are incorporated herein by reference. Such devices are often referred to as transom jacks or motor jacks or outboard engine jacks. Most of the prior devices of that type are mechanically quite complicated.
An object of the present invention is to provide an outboard motor mounting apparatus which can be used to raise and lower the outboard motor relative to the transom of a boat.
Another object of the present invention is to provide an outboard motor mounting apparatus that has an attractive appearance and a minimum number of parts which are subject to being damaged or loosened by the employment of the device.
A further object of the present invention is to enable adjustment of the operating characteristics of an outboard motor powered boat while the boat is in operation to match the operation of the boat and the motor to instantaneously occurring conditions exiting during the operation of a boat.
Other objects, advantages, and features of the present invention will become clear from the following description when read in conjunction with the drawings and the appended claims.